Abstract
Numerous prognoses indicate that climate change will manifest itself in extreme climatic conditions. Therefore, it will be of high importance to know in what extent can plant communities and certain species adapt to altering environmental conditions. Our examinations were implemented in stands of sessile oak common in the Carpathian Basin. The reason behind it has been that, according to climatic models, the realized niche of this species can be reduced by 80% in some regions by 2050. Examinations were made in 3 points of an approximately 400 km long (East-West) transsect crossing the Carpathian Basin: 3 submontane regions of a subatlantic, a continental and a subcarpathian mountain were involved with 5 age groups in each regions. Health status examinations of sessile oaks have been completed by using FAKOPP 3D acoustic tomograph. Among the three venues trees of the subatlantic area were the healthiest; here, the 100 years old age group showed the lowest deterioration, only 0.68%. The most severely deteriorated stands occur in the continental region where the value in the 60 years old age group reached 4.24%. It seems that, besides annual precipitation, the method of planting also influences the health status of stands, since considerable differences could be observed between coppice and seedling stands.